Abstract
The water availability in dry steppes during various active growing seasons is analyzed for the first time. Climatic fluctuations are examined, and their specific features are determined. Contrary to the popular opinion that the maximum precipitation in the steppe zone occurs during the summer period and that this is a distinctive feature of the steppe zone that is applicable to all its subzones, analysis of dry steppes in the Lower Volga Region over a period of 64 years shows that the maximum precipitation is attributed to summer only in 39% of the studied years, to spring in 27% of the years, and to fall in the remaining 34% of the years. Analysis of the water availability time series produced for various seasons covering more than a semicentennial period shows a general trend: the summer precipitation is decreasing, while the precipitation in spring and fall is increasing. The application of the exponential smoothing method to the time series and regression analysis indicate a growth dynamics of water availability in the spring period after the watershed years of 1989 and 1990 (the data validity is confirmed by the Student’s t-test; the probability value is 0.0005) amid a decrease in the fall precipitation (the probability value is 0.01). These trends characterize the demutation processes ongoing in the secondary fallow phytocoenoses, which are manifested by the predomination of loose- and firm-bunch grasses: water availability in late spring (May) and early summer (June) plays a critical role in the generative process of these plants. In total, 28 species belonging to the Poaceae family have been identified in the studied phytocoenoses; their share in the total species richness is 24.5%. The water availability patterns indicate aridization of the climate in dry steppes. The presence of ephemeral and ephemeroid plants in the communities additionally confirms this: the spring precipitation is their key life support factor. The ephemeral and ephemeroid species constitute 8% of the total species richness.
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REFERENCES
Cherepanov, S.K., Sosudistye rasteniya Rossii i sopredel’nykh gosudarstv (v predelakh byvshego SSSR) (Vascular Plants of Russia and Adjacent Countries within the Former Soviet Union), St. Petersburg: Mir i Sem’ya, 1995.
Chimitdorzhieva, E.O., Carbon reserves in postagrogenic dry steppe soils of Western Transbaikalia, Arid Ecosyst., 2017, vol. 7, no. 3, pp. 178–183.
Kashirskaya, N.N., Khomutova, T.E., Demkina, T.S., Salmanova, K.A., Kuznetsova, Yu.S., and Demkin, V.A., Biological activity of modern and buried dry-steppe chestnut soils, Arid Ecosyst., 2013, vol. 3, no. 2, pp. 106–112.
Keller, B.A., General types of vegetation of USSR, in Rastitel’nost’ SSSR (Vegetation of USSR), Moscow: Akad. Nauk SSSR, 1938, vol. 1, pp. 133-181.
Kovda, V.A., Pochvy Prikaspiiskoi nizmennosti (Severo-zapadnoi chasti). Nauchnyi otchet o rezul’tatakh issledovanii, provedennykh v 1932–1938 gg. (Soil of Caspian Lowland (Northwestern Part): Scientific Report on the Study Results Performed in 1932–1938), Moscow: Akad. Nauk SSSR, 1950.
Kulik, K.N. and Pugacheva, A.M., The structure of plant communities of fallow land in the system of protective forest plantations in dry steppes, Arid Ecosyst., 2016, vol. 6, no. 1, pp. 63–69.
Kuperman, F.M., Dvoryankin, F.A., Rostovtseva, Z.P., and Rzhanova, E.I., Etapy formirovaniya organov plodonosheniya zlakov (Formation Stages of Cereal Fruiting Organs), Moscow: Mosk. Gos. Univ., 1955.
Lavrenko, E.M., Karamysheva, Z.V., and Nikulina, R.I., Stepi Evrazii (Steppes of Eurasia), Leningrad: Nauka, 1991.
Maissner, R., Rupp, Kh., Shmidt, G., Bondarovich, A.A., Shcherbinin, V.V., Pon’kina, E.V., Matsyura, A.V., Rudev, N.V., Kozhanov, N.A., Puzanov, A.V., and Balykin, D.N., Agroclimatic monitoring of dry steppe of Altai krai, Geogr. Prirodopol’z. Sib., 2017, no. 23, pp. 121–139.
Orlov, D.S. and Biryukova, O.N., Reserves of carbon from organic matter in soils of Russian Federation, Pochvovedenie, 1995, no. 1, pp. 21–32.
Prozorovskii, A.V., Semideserts and deserts of USSR, in Rastitel’nost’ SSSR (Vegetation of USSR), Moscow: Akad. Nauk SSSR, 1940, vol. 2, pp. 207–480.
Pugacheva, A.M., Recovery of ecosystems on fallow lands with chestnut soils of dry steppes, Vestn. APK Stavrop., 2016, no. 1 (21), pp. 234–240.
Pugacheva, A.M., Agroforestmeliorative systems as a basis for development of land agriculture, Izv. Nizhnevoszhsk. Agrouniv. Kompl. Nauka Vyssh. Prof. Obraz., 2018, no. 1 (49), pp. 227–237.
Safronova, I.N., Zonal distribution of vegetation cover in Volga–Ural interfluve, Bot. Zh., 1975, no. 6, pp. 823–831.
Safronova, I.N., About frontiers between steppe and desert zones in Lower Volga region, Povolzh. Ekol. Zh., 2008, no. 4, pp. 334–343.
Safronova, I.N., Zonal division of arid territory of European part of Russia, Bot. Zh., 2012, vol. 97, no. 6, pp. 705–711.
Safronova, I.N., Dominants in modern vegetation cover of deserts in European part of Russia, Materialy Mezhdunarodnoi nauchno-prakticheskoi konferentsii “Prirodnye i antropogennye izmeneniya aridnykh ekosistem i bor’ba s opustynivaniem” (Proc. Int. Sci.-Pract. Conf. “Natural and Anthropogenic Changes of Arid Ecosystems and Combat Desertification”), Tr. Inst. Geol. Dagest. Nauchn. Tsentra, Ross. Akad. Nauk no. 67, Makhachkala: Alef, 2016, pp. 250–253.
Sambuu, A.D. and Ayunova, O.D., Stages of pasture digression in dry steppes of Tuva, Mezhdunar. Zh. Prikl. Fundam. Issled., 2016, no. 5-2, pp. 293–295.
Sapanov, M.K. and Sizemskaya, M.L., Climatogenic changes of herbaceous vegetation on solonchaks of Northern Caspian region, Povolzh. Ekol. Zh., 2010, no. 2, pp. 185–194.
Sveshnikova, V.M., Bobrovskaya, N.I., and Tsend, Sh., Water regime of the plants in the southern part of the People’s Republic of Mongolia, Bot. Zh., 1976, vol. 61, no. 1, pp. 106–111.
Ulanov, A.K., Budazhapov, L.V., Biltuev, A.S., and Sordonova, M.N., Response of humus state of chestnut soil on prolonged use of various methods in land agriculture in dry steppe of Buryatia, Zemledelie, 2018, no. 5, pp. 11–15.
Vasil’ev, D.Yu. and Ferapontov, Yu.I., Dynamics of air temperature in Bashkiria, Izv. Ross. Akad. Nauk, Ser. Geogr., 2015, no. 1, pp. 77–86.
Voskoboinikov, Yu.A., Ekonometrika v EXCEL: uchebnoe posobie. Chast’ 2. Analiz vremennykh ryadov (Econometrics in EXCEL: Manual, Part 2: Analysis of Time Scales), Novosibirsk: Novosib. Gos. Arkh.-Stroit. Univ., 2008.
Vysotskii, G.N., Yergeni: cultural and phytological description, Tr. Byuro Prikl. Bot., 1915, vol. 8, nos. 10–11, pp. 1113–1443.
Zayats, O.A., Cyclicity research of crop yield of grain cultures in Volgograd oblast by spectral analysis, Biznes. Obraz. Pravo. Vestn. Volgograd. Biz., 2011, no. 4 (17), pp. 186–191.
Zolotokrylin, A.N., Titkova, T.B., Cherenkova, E.A., and Vinogradova, V.V., Dynamics of summer moistening and biophysical parameters of arid pastures in the European part of Russia in 2000–2014, Arid Ecosyst., 2016, vol. 6, no. 1, pp. 1–7.
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Pugacheva, A.M. Climatic Fluctuations in Dry Steppes and Their Role in the Demutation Process. Arid Ecosyst 10, 181–187 (2020). https://doi.org/10.1134/S2079096120030063
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DOI: https://doi.org/10.1134/S2079096120030063